Counters integrated in electronic circuits are generally made in the form of an assembly of flip-flops which are either set to zero or pre-loaded so that the counter exhibits a given value. According to cases, the counter is incremented or decremented on each edge of a given direction (rising or falling) of a clock signal.
Counters of electronic circuits have multiple uses. For example, they may be used to rate a central processing unit (program counter), to count a number of events occurring in an integrated circuit, be it or not to condition the subsequent circuit operation, etc.
According to a first example of application, a disturbance of the operation of a counter may result in modifying the operation of a program processing unit. Such a disturbance may be incidental or voluntary (fault injection), in particular in cryptographic or secured applications of operation of an integrated circuit.